Date: Fri, 4 Jan 2019 10:34:19 -0330 (NST)
From: jcraig@mun.ca
To: rsgb_lf_group@blacksheep.org
In-Reply-To: <976652757.10789891.1546166793929@mail.yahoo.com>
Message-ID: <Pine.LNX.4.64.1901041015150.10683@plato.ucs.mun.ca>
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 <976652757.10789891.1546166793929@mail.yahoo.com>
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Subject: Re: LF: VLF Carrier on 8270.01 Hz from a ground loop antenna - The
 6th station on Paul's spectrogram
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Hi Markus, Stefan, Group,

Putting some marks on the DL0AO spectrogram is very gratifying and an
indication that the RX setup is very good. I am trying to understand=20
what is being oberved and am happy to have your explainations.

The Doppler wiggles are associated with the motion of the ionosphere or
are they the result of phase changes from the change in path lenght
as the ionosphere (or virtual reflection point) moves up and down?

I went back through Pauls data to see if I could find other instances
where the central carrier vanished as it did this fall and found none,
not even during the spring equinox. It is as if the phase modulation
has been switched off.

Jim provided a diurnal phase ploy model output last fall.  This must
change with the season.  It seems remarkable that the phase shifts
in the fall were so close to 180 degrees.  I hope they come back!

Thanks for the advice on the rail, Stefan. I'll test the continuity
if the wx improves.  It is at a remote site and runs along the ocean in
your direction and is there to prevent cars from going over the 50m
cliff edge.  Years ago, a chemistry professor told me he could hear BBC4
during the daytime when he brought his portble radio near the rail.

73 and HNY
Joe

On Sun, 30 Dec 2018, Markus Vester wrote:

> Hi Joe,
>
> you probably=C2=A0refer to=C2=A0your carrier on 8270.0075 - yes I think y=
ou're right, there are littl
e Doppler wiggles, with higher frequency during the mornings than=C2=A0in t=
he evenings. This doe
s make sense, considering=C2=A0day-night phase shifts observed=C2=A0in=C2=
=A0the=C2=A0long 13.3 hour FFT integration time.
>
> In Paul's 1.5 uHz spectrum covering=C2=A0one week, we now see a central p=
eak on the nominal frequency, assosiated by smaller AM and PM sidebands at =
11.6 uHz spacing.
>
> Would the connection=C2=A0between your guard rails be approximately orien=
ted=C2=A0towards us?
>
> 73, Markus
>
>
>
> -----Urspr=C3=BCngliche Mitteilung-----
> Von: jcraig <jcraig@mun.ca>
> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
> Verschickt: So, 30. Dez 2018 2:21
> Betreff: Re: LF: VLF Carrier on 8270.01 Hz from a ground loop antenna - T=
he 6th station on Paul's spectrogram
>
> Hi Markus, VLF,
>
> Thanks for mentioning the 8270.0027 Hz traces at DL0AO. I've been watchin=
g
> closely ever since. There appear to be dirunal frequency shifts on
> this signal (or perhaps it is my imagination).
>
> There are guard rails here that run in a straight line for about a km
> that would make fine ground loops for VLF but getting across the pond
> might be challenging.
>
> 73
> Jor VO1NA
>
>
> On Sat, 29 Dec 2018, Markus Vester wrote:
>
>> Hi Stefan,
>>
>> a similar "miracle" occured at DL0AO: The trace from your ground loop ap=
peared=C2=A0very strong on the NS-loop, which should have a null towards yo=
ur transmitter. The peak was - 120 dB on EW and V, and=C2=A0-125 dB on NS, =
only 5 dB difference.
>>
>> I believe our=C2=A0N-S receive loop is seeing only the=C2=A0skywave comp=
onent. Due to the angular orientation of your=C2=A0transmit=C2=A0loop, the =
electric field of the upward radiation will be=C2=A0polarized in the NW-SE =
direction, with the orthogonal magnetic field=C2=A0pointing NE-SW. This pol=
arization will be more or less retained during the reflection (possibly=C2=
=A0rotated a bit by Faraday effect). So=C2=A0the downgoing wave will also c=
ontain=C2=A0a magnetic field component=C2=A0in the E-W direction, which=C2=
=A0is then picked up by=C2=A0the NS-loop.
>>
>> So yes, earth loops are loops.
>>
>> Best 73,
>> Markus (DF6NM)
>>
>> -----Urspr=C3=BCngliche Mitteilung-----
>> Von: DK7FC <selberdenken@posteo.de>
>> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
>> Verschickt: Sa, 29. Dez 2018 19:27
>> Betreff: Re: LF: VLF Carrier on 8270.01 Hz from a ground loop antenna - =
The 6th station on Paul's spectrogram
>>
>> Hello Jacek,
>>
>> Oh, indeed, very clear! I did not expect this at all. The loop, if it
>> behaves as a loop at all (!), points towards Paul. It should have a null
>> into your direction. Our distance is 976 km !
>> http://k7fry.com/grid/?qth=3DKO02MD&from=3DJN39WI
>> Why do you see the signal at all? I'm puzzled but it feels good :-)
>>
>> Tomorrow, maybe i'll do something on 2970.01 Hz!
>>
>> 73, Stefan
>>
>>
>> Am 29.12.2018 18:25, schrieb Jacek Lipkowski:
>>> Good signal on my grabber:
>>>
>>> https://klubnl.pl/wpr/en/index.php/klubnl-pl-grabbers/grabber-4-8270hz/
>>>
>>> What is the antenna orientation?
>>>
>>> jacek
>>>
>>> On Sat, 29 Dec 2018, DK7FC wrote:
>>>
>>>> Date: Sat, 29 Dec 2018 13:43:14 +0100
>>>> From: DK7FC <selberdenken@posteo.de>
>>>> Reply-To: rsgb_lf_group@blacksheep.org
>>>> To: rsgb_lf_group@blacksheep.org
>>>> Subject: LF: VLF Carrier on 8270.01 Hz from a ground loop antenna -
>>>> The 6th
>>>> =C2=A0 =C2=A0 station on Paul's spectrogram
>>>>
>>>> Hi VLF friends,
>>>>
>>>> Since 11:35 UTC i'm running about 2.5 A antenna current into my 900m
>>>> long ground loop antenna. Frequency is 8270.01 Hz. The signal is very
>>>> strong on my own grabber in 57.6 km distance but also at DF6NM, DL0AO
>>>> and it looks like there is a peak now on Paul's spectrogram building
>>>> up slowly.
>>>> I intend to run the carrier for 2 hours or so, until the accu is
>>>> almost empty :-)
>>>> The H bridge PA voltage is 175 V and the power consumption is 450 W.
>>>> Today, the DC measuremant result is 66V for 1 A antenna current. It
>>>> is cold and wet!
>>>> More soon.
>>>>
>>>> 73 de DK7FC/P in JN39WI
>>>>
>>>> PS: The QRN is exceptional low!!!!
>>>>
>>
>>
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